Upper cowl and air vent rust repair

[GCC]

Got a pretty good start on fixing the rust damage after cutting open the driver's side upper cowl.  The air vent ring (top hat?) is o.k., but has some tiny rust holes in it.  Are these available in reproduction anywhere?  Also, what is the appropriate sealer to use at reassembly: generic caulking?  3-M seam sealer?  Something silicon-based?  I would guess it should remain pliable.  Thanks!   

[elitecustombody]

before applying seam sealer,make sure to use etching or epoxy primer,if you end up using 3M sealer,do not get "Fast'n Firm", it will become hard ,brittle and will crack in a year, use 3M Ultrapro  Sealant, it's very nice and easy to work with

[moparclown]

Nice,when I was doing the cowl over in one of my Challengers a couple years back,that air vent ring wasn't available.But with the parts that have come out to repair cowls and firewalls,I would bet you could get one now.
I built the one for the pass side from scratch,yours doesn't look bad?I would just fix that one myself